According to archaeologist Jose Luis Romero Rivera, director of the INAH project at the site located in Tenosique municipality, Structure 12 is a 2.5 meters high base, with other 2 bases slightly tallest at the north and south extremes. Photo: Jose Luis Romero.

MEXICO CITY.- Researchers of the National Institute of Anthropology and History (INAH) study a Prehispanic monticule known as Structure 12, at San Claudio Archaeological Zone in Tabasco, which may have had been used as an astronomical observatory to register the Sun movements at solstices when this city was dwelled by Maya people, between the first centuries of the Common Era to year 900.

According to archaeologist Jose Luis Romero Rivera, director of the INAH project at the site located in Tenosique municipality, Structure 12 is a 2.5 meters high base, with other 2 bases slightly tallest at the north and south extremes.

It is probable that people accessed the structures by the esplanade or central yard. It is a stone construction with batter walls and rounded corners resembling the Peten style but of smaller dimensions.

Other unique feature is its orientation: all structures present an 11 degrees deviation to the northeast, while number 12 is deviated by 25°; the difference allows us to assume it had an astronomical function. It looks like it was an elite residential space with an access of 3 entrances and 2 columns.

Romero Rivera mentioned that this orientation coincides with solstices. On the dawn of the next winter solstice, observation will be conducted to determine if Structure 12 walls are aligned with the rise of the Sun. Most Prehispanic cultures celebrated commemorative rites in such dates.

The archaeologist pointed out that excavation and consolidation of Structure 12 will continue, so 3 buildings will be exposed to public visit in late 2010. The other structures are Number 1 and Number 4.

Located near Mexican border with Guatemala, San Claudio was occupied from 200 BC to 900 AD in the Late Classic period, and must have been part of the influence area of Piedras Negras Maya city, to present located in Guatemala.

Abundance of flint stone rests found at excavations indicates this mineral was the main raw material handed over to hegemonic cities by San Claudio; we are talking about societies where metal did not exist. Elaboration of sharp tools depended on flint, a strategic material, he added.

As part of San Claudio Archaeological Project, which formally began in 1997, 35 human burials have been located, with the same 11° northeast orientation that the ancient city presents.

Most complex burials found to present consist on tombs made with limestone slabs accompanied with simple offerings, being the richest integrated by 3 vessels, while the most modest ones only presented a bowl or dish covering the face.

A constant in the funerary tradition is that burials were deposited under the houses floor, coinciding with historical references from early Spanish chroniclers. A platform occupied for dwelling for over 200 years may present many entombments, as Structure 4, where nearly 20 have been found, concluded the INAH archaeologist.